Astrocyte-selective transduction with AAV5 viral vector does not exacerbate astrogliosis or alter tissue immune responses following spinal injury

Following contusive spinal injury astrocytes undergo inflammatory activation and proliferation in a process known as astrogliosis. Reactive astrocytes are attractive therapeutic targets as they sit central to many of the immune recruitment, injury response, and tissue healing processes of the spinal cord. However, methods of targeted expression of exogenous therapeutic genes within astrocytes must be validated to not alter the normal immunological involvement of astrocytes. To investigate the effect of transgene expression within astrocytes upon the immunological state of the contused cord, we injected the astrocyte-selective AAV5-GfaABC1D-dYFP reporter vector into an animal model of moderate contusive spinal cord injury. Bulk RNA microarrays were used to assess transcriptomic changes of the perilesional tissue. Adult female Sprague-Dawley rats (220-250 g) underwent surgical T10 laminectomy and moderate contusive injury (175 kDyn) by an Infinite Horizons impactor. Treatment groups were acutely administered the AAV5-GfaABC1D-dYFP reporter vector at the time of surgery by stereotaxic microinjection. Following recovery, at 7- and 28-days post-injury animals were euthanised and the spinal tissue taken for Clariom S Rat microarrays or fixed in paraformaldehyde (4%, pH7.4) for immunohistochemistry.